login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A056844 Number of polydiamonds: polyominoes made from n diamonds. 2
1, 2, 9, 40, 238, 1517 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Comment from Larry_Reeves(AT)intranetsolutions.com, Jun 22 2001: If you look at Vicher's picture of the 40 4-celled polydiamonds (link in A056844), near the middle of the picture is a polydiamond that looks like the tradiitional 2-D representation of a cube with an extra diamond stuck to the edge. Depending on how you orient the cube, there are actually 2 different ways to form this polydiamond, although there is no change in the perimeter shape. I haven't confirmed that this explains the difference in values for sizes 5 and above for A056844 and A056845, but it looks like a possible explanation.

LINKS

M. Vicher, Polyforms

M. Vicher, The 40 4-celled polydiamonds

M. Vicher, The 40 4-celled polydiamonds

CROSSREFS

Cf. A056845.

Sequence in context: A166554 A038156 A052846 * A002825 A052322 A130767

Adjacent sequences:  A056841 A056842 A056843 * A056845 A056846 A056847

KEYWORD

nice,nonn

AUTHOR

James A. Sellers (sellersj(AT)math.psu.edu), Aug 28 2000

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com), Jun 21, 2001

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 13 08:12 EST 2012. Contains 205451 sequences.